Recently, a graphene wiring structure using graphene wires instead of metal wires has received much attention. Since graphene has a quantization-conduction characteristic (ballistic conduction characteristic) like a carbon nano-tube and conducts electricity by quantization, it is advantageous in comparison with electrical conduction of a long-distance wire. Further, the graphene structure itself is an extremely thin film and can be formed by use of a CVD method. Therefore, a graphene wire has a high degree of matching with respect to a device wire formation process.